s-t,v-t圖像問題

2020-12-24 每日一初中物理

s-t,v-t圖像問題是一種很常考的問題，關於s-t,v-t圖像的技巧規律，上面的表格中羅列得很詳細。我們以一道問題為例，來看一下這種題型要如何解決。

.(2019湖州改編)甲、乙兩物體運動時，路程與時間的關係圖像如圖所示，其中甲為曲線，乙為直線，在t＝5 s時兩線相交，則由圖像可知(　　)

請

A．兩物體在t＝5 s時一定相遇

B．0～5 s內甲的平均速度大於乙的平均速度

C．甲物體做曲線運動，乙物體做直線運動

D．甲物體做變速運動，乙物體做勻速運動

答案：D

答案解析：首先我們明確了這是一個s-t圖像，表示物體運動的路程隨時間的變化關係。

A. 兩物體在t＝5 s時，運動路程都是3m，但題目中沒有說明兩物體是從同一地點出發，所以不一定相遇，故A錯。

B. 平均速度的求法是用總路程去除以總時間，0～5 s內，甲乙的運動路程相同，都是3m，運動時間都是5s，所以平均速度都相同，故B錯。

C. 甲這條曲線並不代表甲物體做曲線運動，而是說明甲物體做變速運動，所以C錯。乙的這條曲線說明乙物體做勻速直線運動，故D對。

牛刀小試：

(2019大慶改編)在一年一度的「端午龍舟賽」中，在平行賽道上，甲、乙兩隊龍舟的速度與時間的關係圖像如圖所示。根據圖像可知，下列說法正確的是(　　)

A．0～t1內兩隊所走距離相等

B．t1時刻甲隊比乙隊運動得快

C．甲隊做勻速運動，乙隊做變速運動

D．t1時刻甲、乙兩隊速度相等

相關焦點

  • 直線運動的x-t圖像和v-t圖像
    今天，我們從圖像的「六看」口訣來研究圖像。同學們都知道，不管是位移時間圖像（x-t圖像）還是速度時間圖像（v-t圖像），其圖線都不表示物體的運動軌跡。那麼，是否有一種圖像表示物體的運動軌跡呢？還真有，那就是位置坐標圖像（x-y圖像）。
  • 速度圖像解釋「交警如何發現小車速度223km/h,超速123%的?」
    ①s -t圖像是一條過原點的直線，在任何時刻的速度相等(如圖甲、乙)，②大小：選取任意時間段對應通過的路程，且圖像的斜率越大，速度越大，即v甲>v乙。(3)變速直線運動：s -t圖像是曲線或分段的折線(如圖丙、丁)。
  • T字母不會說話,參天大樹來幫忙!T字母的本義和引申義!
    今天我們從形、聲、義上來學習T字母，從而對圖像象形記憶法有個深刻了解。讓誰先「說」出來？tell、talk、say、speak誰也不讓誰！Tt字母之形：Tt字母之聲：[ti：]Tt字母之本義： 樹形（下面一豎指樹杆，上面一橫樹枝）Tt字母之引申義：1.
  • 歌曲 | 《we don't talk anymore》
    I overdosedShould've known your love was a gameNow I can't get you out of my brainOh it's such a shameWe don't talk anymoreWe don't talk anymoreWe don't
  • We Don't Talk Anymore
    Oh, it's such a shame噢如此不堪的自己We don't talk anymore, we don't talk anymore我們之間只剩沉默 再回不到耳語廝磨We don't talk anymore, like we used to do我們之間只剩沉默 一切都已再難如昨We don't love
  • We Don't Talk Anymore(周芷伊 2017)
    We don't talk anymore  Like we used to do I just heard you ( ya ) found the one you'vebeen lookin' You been looking for I wish i would've konwn that wasn't meCause even after
  • 每周金曲- We Don't Talk Anymore
    you're wearing tonightIf he's holding onto you so tightThe way I did beforeI overdosedShould've known your love was a gameNow I can't get you out of my brainOh it's such a shame
  • 高考英語3500詞彙(T):單詞+詞組+句型
    磁帶錄音機target [ˈtɑːɡɪt] n./ v. 目標, 把…作為攻擊目標task [tɑːsk; (US) tæsk] n. 任務, 工作taste [teɪst] n. 品嘗, 嘗味；味道 vt. 品嘗, 嘗味I don’t like the taste of olives(橄欖).我不喜歡橄欖的味道。
  • .| 中國各地生活繼續常態化復甦 Cu c s ng ti p t c kh i ph c...
    Ngày 19/7, thành ph B c Kinh, Trung Qu c ra th ng cáo, b t u t ngày 20/7, B c Kinh s h c p h ng ng ng phó s ki n y t c ng c ng t xu t t c p II xu ng c p III, c
  • You don't live here anymore
    Often nights are darker than beforeAnd the days I've learnt to love them moreEven though you're somewhere here besideStay away you don't live here anymoreEverything
  • 《We Don't Talk Anymore》MV,真實而傷感
    I overdosed Should've known your love was a game Now I can't get you out of my brain Oh it's such a shame We don't talk anymore We don't talk anymore We don't talk anymore
  • 越南歌曲:Bật Nhạc Lên
    Khi em khóc hãy bật nhạc lênTừng câu hát sẽ mang đi niềm đauCó những nổi nhớ ta phải quênĐể em bước tiếp những ngày sauu x2Nghe bài hát cũng có thể đoán tâm trạng của em
  • 周華健《(I AIN'T) MISSING YOU》
    I spend my time thinking about you and it's almost driving me wild.And there's a heart that's breaking down this long distance line tonight.
  • Jason Mraz: I Won't Give Up
    I look into your eyesIt's like watching the night skyOr a beautiful sunriseThere's so much they holdAnd just like them old starsI see that you've come so farTo
  • 每天一首好歌 查理·普斯《We Don't Talk Anymore》
    我沉溺其中無法自拔Should've known your love was a game我早該知道你的愛不過是場遊戲Now I can't get you out of my brain而我就是無法將你移除腦海Oh it's such a shame噢 真是羞愧We don't talk
  • 《We Don't Talk Anymore》,真實而傷感
    wanna know What kinda dress you're wearin' tonight If he's holdin' onto you so tight The way I did before I overdosed Should've known your love was a game Now I can't get you out
  • 「It's doesn't matter」 真的是「沒關係」嗎?(漲姿勢)
    But in the end, it doesn't even matter.我曾那麼努力，也取得了不少成績。但是到了最後，這一點都不重要。可以看出It doesn't matter.或It didn't matter.
  • 【每周一歌】《Don't Cry》Gun&Rose
    只是難免有很多人在聽到"Give me a kiss before you tell me goodbye"時就cry了。無論是曾經失戀,或者是曾經深愛,我相信聽了這首歌都會引起你的共鳴。我就不多扯了,這樣的歌,其實扯再多都是沒用的,用心一聽,自然就會愛上的。
  • 英文學唱/We Don't Talk Anymore
    慢速0.8倍（大概...）版；原唱由於版權問題po不上來，小夥伴們移至文末看mv啦！
  • 聽歌學英文第17期《We Don't Talk Anymore》
    Oh, it's such a shame噢如此不堪的自己We don't talk anymore, we don't talk anymore我們之間只剩沉默 再回不到耳語廝磨We don't talk anymore, like we used to do我們之間只剩沉默 一切都已再難如昨We don't love